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email sent, if I had realised how small the file was I would have sent it to you before anyway.
I also mentioned that we checked +FL but not -FL which I think are something to do with the filaments in the display.
C24 is worth checking as it connected between these to supplies and if faulty could cause the display problem.
Well, I’ve had a chaotic few days, but have found some peace and quiet this morning. However, I cannot report progress, in fact it looks like a step backwards.
First, I installed a new 470 10v cap at C21, instead of the temporary. Foolishly, I didn’t do to the resistance check before fixing it, but seems to be OK. I also had to take a couple of minutes out to do a temporary fix to the mains input as the socket had come off the board.
The result was where we were a few weeks ago – no +5V or +3VS on the output cable. So had to restore the link between R95 and R98, and then I had those voltages. No SATA power though, but that may be because my test HDD has failed.
Voltages on FL+ are 22.v and FL- 16.5v. I could check those at both the PSU and front panel ends.
I’m still getting 5.1v DC at the input to the front panel but no voltage on the two output pins. Curiously, and I discovered it by accident, if I put a probe on one pin only, I’d get a steady 3.0v AC, but as soon as I got the other probe on the other pin, the voltage ran down to zero.
Thanks, Stroker, for the flash tools. I’ve installed them, and then tried connecting the receiver and PC with the USB A-B cable. Of course, I’m working blind, but holding down standby and the right arrow for several seconds produced no reaction on the PC – so I never get the opportunity to load the drivers. Nothing shows up in Device Manager.
I am beginning to think we made the wrong decision when we tried flashing because we seem to have lost any signs of life we had previously. If we had done it with flash-tools the result may have been different! Anyway onwards and upwards there's a few things we can check while I come up with a new plan of attack!
1. On the display board I would like you to measure the voltage (to GND) on the first and last pin of the display itself, I expect this to be FL- and FL+ but I could be wrong.
2. Remove the battery/cell for a while and if you can remove the tuners - some people have mentioned problems with these. Later refit the battery but not the tuners power on and see what happens - no change I expect but always worth a try.
3. Check CE1, CE2 and ZD1 on the display board, you may be able to check the caps on-board otherwise remove them. ZD1 is a zener diode but can be checked in the same way as a normal diode - only 2 pins need testing, I think the 2 nearest the transformer but not sure. If you cannot test ZD1 try melting the solder to freshen it up but be careful that all 3 are not melted at the same time or it may slide of the pads.
4. There is a 20 pin header(connector with nothing connected) towards top left of the motherboard is there anything to identify it's purpose? I think it may be a JTAG connector (used for low level programming). Perhaps you can take pic and perhaps a close up pic of the 64 pin chip you posted recently.
From your post FL voltages are probably OK.
The 3V ac reading is probably just sent to try us. You could check continuity between the 2 pins on the transformer
It reminds me of a mains powered unit I was fixing a while ago there appeared to be believable voltages everywhere in the unit but it turned out the mains transformer primary winding was open circuit - fitted a new transformer and it was fixed - wasted a few hours on that one!
Just thought - when checking out the suspected JTAG connector please measure the voltage on each corner pin - this may give a clue what it's about. I expect one corner to be 5V or 3.3V another should be GND and the others two may be a bit random.
Sorry – only just got this posting. As to previous posting, if by the pins on the display itself you mean the long line of pins on the underside below the two sets of connectors, then there is no continuity between neither +FL (Pin9 on the long connector), nor-FL (Pin 10)and the first couple or last couple of the long line. Voltage to the long pins was 25.2Vor so. I tested several of them at random, and they came in the same, or a bit lower. At the same time +FL was reading 22.2V.
I had come across the possibility of faulty tuners, so I had removed both for most of the checks I’ve reported.
There is continuity across the two pins of the output of the front panel transformer.
ZD1 OK – one probe on the single pin and the other on the pin next to the transformer – 0.6V and infinity.
CE1 and CE2 left in situ, and both show increasing resistance and with probes reversed.
I should have mentioned yesterday that I tried both C24 and C25 on the PSU board while in situ, and they both passed the test.
Can’t make anything out of the twenty pin header – not helped by my magnifying glass going AWOL. Will try and upload some pics tomorrow I’ve come out without camera.
Thanks for the info - will digest later.
I have sent you an email with slightly different (USB) flashing instructions.
We still have the possibility of flashing using RS232 but I think this only allows flashing the boot loader.
It is usual for RS232 to work when nothing else does but you will need RS232 on your PC/laptop.
I am interested in this possible JTAG connector there would be a reset pin on it which could be useful to us.
I am having trouble uploading pic of what I am expecting so will send by email.
If we briefly short reset and GND we may get the box into a better state.
Looking at the 20-pin header from the front, the top left pin is GND. To the pin just below it there is 1.8v. There is no voltage to the pins on the right hand side.
Just thought I’d check voltages at the standby switch. On the middle pin of the bottom row, I get 5.1v, which is the +5VS voltage. However, I don’t see continuity from that pin to any of the other five, whether or not the switch is held down. There’s something like 1.7v on the other two bottom pins, and nothing on the top.
I also thought I ought to re-check the voltages at the output end of the PSU in case something had changed. In the course of that I found I did have SATA power. But, with front panel disconnected, reconnecting the PSU to the main board caused SATA power to be lost.
Attachment 66372Attachment 66372
Sorry second pic hereAttachment 66374
Need to think about your header reading - not quite what I was expecting.
Don't understand what's happening with the SATA supply - will look at that later perhaps.
With the standby switch I think the middle pins will be the LED and checking your post from 09 Jan (I think) the switch contacts are top and bottom corner pins.
I think you will have continuity between top and bottom corner pins with switch pressed.
I believe the flash is stored in the socketed 44 pin device to the right of the battery.
Do not try to remove this device yet as it can be easily damaged - there is a special tool to remove it but you can do it without the tool although you can damage the pins of the device and the socket if not done properly. In fact it's not much easier with the tool. Anyway you could try pushing the device down into the socket - sometimes they work loose and lose contact on one or more pins.
Assuming the switch is working I think we need to try blind flashing the boot loader I don't think we can make it any worse!
You need to rename the file to usb_uboot.img, I am thinking that the software for the display etc must be in the boot loader.
We should be able to use RS232 to flash as a last resort later anyway or at least I hope so. Flashtools can be used with RS232 but of course we have to sort out a cable and suitable PC/laptop to go down this route
Apologies for a longish silence – poor internet access, and, as you’ll see, a lot of confusion on my part.
I’ve had another look at the 20-pin header, and found the following:
Top row, even nos 2-20 – all GND.
Bottom row odd nos:
1 1.75v
3 unstable, hovering around 1.0v
5 as 3
7 1.75v
9 nil
11 nil
13 nil
15 as 3
17 1.75
19 nil, but once got 0.88v.
I also noticed one or two changes. I had previously measured voltages from the hotside heatsink – getting 333v to TH81, 21v to R98 or 11.6 with the link to R95in. Now, I got unstable readings from it. From the chassis screw, I get 325 and 7.6v to R98 and to R95 with the link in.
Well that’s what I found an hour ago.
Now, I repeat the check and get something different. I get stable readings from the heatsink, but not from the chassis. And I get no voltages at all on the odd number pins of the JTAG header.
Furthermore, I get a different picture near the heatsink. I’ve removed the link between R95 and R98. From the heatsink to R95 I get 1.26v, same to both ends. To R98 I used to get 21.6v, which would be present through to the cold side of R96. Now I get 1.27v to the hot side, 0.61v to the cold side and nothing to the cold side of R96.
Earlier today, I got SATA power with the main board disconnected; now I don’t.
As far as I can tell, I’ve done nothing to produce this change within the hour.
Now I have made a change. I removed the coin cell, removed both tuner cards and put back the cell. So check, No 3:
R98 comes at 21.1v – same through to the cold side of R96. R95 comes in at 0.4v on the hot side 0.9v on the cold side –yes, treble checked, that way round. Still no SATA and no voltages on JTAG. After replacing the link, there is 11.6v at R96 but still nothing at the JTAG.
Stroker, if your patience is beginning to get stretched, I fully understand.
If you’re prepared to stay with it one more day, I remember your first prime suspect was IC91. I do have a replacement, so could try that. Also replacements for Q3 and Q4 if that helps us get an AC voltage on the front panel.
Just an added point about the standby switch and its LED. When the system is powered up, the LED flashes for a minute or so and then stops flashing. During the flashing phase, the voltage at the lower middle pin alternates between 5.10v and 1.98v. When the flashing stops, it’s a steady 5.1v
Another noticeable feature now is that there is no voltage at the fan header. Previously, I’ve always had 11.9v there, and two days ago the fan even came on for the duration of one powering up. Also at the output connector (CN41) +8V comes in at 7.2v, whereas previously it was 8.3v.
I've only had a quick look at your post - I won't have much time today.
I would not rush into changing IC91 as long as you have 3.3V and 5V with the link fitted. As far as I can see the SATA 12v is only used for the hard drive - things to check are D41, C41 and IC41 - I like the way they have numbered the devices, trying to keep the numbers the same for everything in the same circuit. The SATA 12v supply comes off the same transformer as the 3.3V and 5V (but not 5VS). Looking at the PIC of you board the soldering on IC41 does not look too good so you could remove some solder and re-solder or just use flux to tidy it up.
I am not sure what's happening with your voltage measurements I will re-read your post when I get the chance.
The connector does look like a JTAG so pin 15 should be reset. You could check what happens when you short it to ground for a short time - you could use a jumper as used on PC motherboards shorting pin 15 and 16. I would expect the box to reset and go through the flashing LED sequence again.
I have to admit this has become a bit of an obsession and progress at the moment has ground to a halt but I still think we can fix this so I am not giving up trying at least for the moment.
Thanks, now out until Sunday p.m.
I have been net surfing again and found someone who recovered one of these boxes with similar problem - no USB access and unusable display.
It involves using the RS232/serial interface and a terminal program to gain command line level access to the box, enable the USB interface and then use flashtools over USB to flash the box as normal. If you do not have RS232 on your PC you can get a USB to serial interface cable - choose one with female 9 pin connector so it will plug directly into the box. I have seen some advertised as for use with Dreambox etc.
Connect box to PC with serial and USB at the same time.
Open terminal program such as "tera term", putty or hyperterminal.
Select the corresponding comm port and set the speed to 115200.
Power on IPBox and repeatedly press ctrl+z on the PC.
When connected some messages should appear on the PC, you can type help for a list of commands.
You should see "startusb" type this and the PC should detect a new connection.
You should now be able to use flashtools.
Flash uboot first and then your required image.
Turn the IPBox off and on and.....
Small update.
Before closing down on Friday, I did another voltage check and found I dis have SATA and I did have 11.9v at the fan header. Presumably something intermittent again. My suspect is CP22 which I refixed about three weeks ago. One of the solders looks poor as if a bit broke off after I did it. So I will re-do that and IC41 at the same time. Now in this house, if there’s a soldering job to be done, the kit has to be got out and then put away again. So, is there anything else I should try. Is there any harm in trying to replace IC91? Any other caps I should remove before testing?
Also I’m wondering whether the time has come to screw everything down again and try connecting to a TV. Or is that likely to be a waste of time?
I do have the capability of doing the test using Serial and USB cables, so that will be the second job after the re-soldering.
I am not sure what you mean by CP22 did you mean C22 or CN82?
Anyway going by your pics apart from IC41 (SATA 12V suppy) as already mentioned you could check soldering on
D42 - in the 3.3V supply looks like someone has been soldering this could do with tidying.
D43 - in the 5V supply looks like someone has been soldering this could do with tidying.
Transistor above R98 - used to turn on IC91 (5V and 3.3V supplies) - looks like someone has been soldering this could do with tidying.
CN82 - could do with tidying - I think you already had trouble with this.
IC91 I would not recommend changing this - there is probably heatsink compound (like cream or grease) between the metal part of the IC and the heatsink which is used to improve heat transfer. Unless you have some heatsink compound I would not bother as long as we have 5V and 3V3 with or withoutt the link on R95/98. If we can flash properly we should be able to remove this link.
It may be an idea to screw the PSU in place so that the filters work properly - we don't want any interference while flashing. I would put the lid on but maybe only fix with one screw - yes I am a pessimist!
As to strange meter readings I have had trouble with intermittent meter leads in the past causing confusion.
Thanks – good to know that multimeter probes may not always be reliable, because I’ve often wondered and then thought is it me? So today, when I got an unexpected result, I didn’t panic. I did have another multimeter in tow, but in fact, after powering down and back up, everything was normal.
OK – today’s homework – have only managed a couple of hours.
First sorry, I meant C22. While I was about it, I replaced it with a new 22µF 50v. Actually, I bought the box new, so no-one has soldered it except me. So I’ve tidied up CN82 and IC41 (I think I touched that with an iron by mistake while doing C21). However Q91, D42 and D43 all look fine and I thought if I do something, I could only do damage. So I left well alone. As regards IC91, I do have some thermal paste, but it’s left over from the last desktop computer I put together, which must be at least three years ago, therefore it may have dried out so I left that for another day. I tried a “repair” to the track to the transformer on the front panel but didn’t really manage a small enough bit of solder. However, I never severed the track and the transformer still gets 5.1vDC – but still produces no AC voltage.
So there are three stages to I went for:
First, I connected the PSU board to the mains, but not to the motherboard. With, and without the link between R95 and R98 I had the same voltages as before i.e. with the link I had all voltages and SATA, but without it no SATA and no +5V and no +3VS.
Secondly, I connect the motherboard with the link, and again, same results as before. – SATA working. Now I do get voltages in the JTAG – same as before with two exceptions.
Finally, I connected the front panel, and again no surprises. At this point I screwed it down, and also screwed down the PSU board. No changes except now the JTAG voltages are as I reported a few days ago.
I’ve closed down now, but tomorrow will try connecting to a TV. And then tackle the flashing issues.
Now there’s a point. The TV and the desktop are on different floors. I do have a serial to VGA cable so could connect to a laptop and a desktop at the same time. Is there any future in that?
My comments on the soldering are based on the pics you posted so anything I saw may have just been a trick of the light at that particular point in time.
I would not worry too much about connecting a TV I think you should be able to follow the flashing progress in PCTools. You will only need the TV after flashing has been successful.
I had a thought - what if you cannot enable the USB?
Well you should still be able to flash UBoot with PCTools using serial assuming you can get this to work - just select serial instead of USB.
If I read the manual correctly you cannot flash the main image over serial on this box only UBoot.
If you can flash UBoot you may be able to get the USB to work - may need to restart the box - and then flash the image with USB.
Good luck and fingers crossed!
No luck with the serial plus USB connection – probably the result of my having an extension cable, so that input. So I will try swapping Pins 2 and 3. I take it the USB connector at the box should be Type B, marked client, with Type A at the computer. If something does work, would I expect to see any messages in the PuTTY box? And would I expect to see the box in Device Manager? Come to think of it, shouldn’t I see it anyway with the USB cable connected – just like my printer.
You will not be able to use USB until we get it enabled.
The first objective is to get some form of communication going which we are hoping to do over serial.
At each end of the cable ie the sat box and PC there is an input and an output, the output of one end has to be connected to the input the other end and vice versa.
Perhaps this may sound obvious but this is an important point.
A suggested method of working out which is the output of an RS232 port but does not always work :-
Unplug the cable, since each port in your case has a male connector this will be easier.
At the PC end measure the voltage to chassis of pin2 and 3, expect one to be near 0V (input) and the other negative (output, up to -12V).
Repeat the measurements at the box end and note the results. If you get good results check that you cable connects input one end to output at the other and vice versa.
You could of course just swap pin 2/3 at one end but I hope doing this test would be a more certain way of proving the connections are correct.
We are also working on the assumption that the box is alive to the extent that the RS232 port is working (which will usually be the case).
It may be working while the LED is flashing and not when it stops or the other way around. It may also work when the box is in standby.
Some but not all boxes output a data string over the serial port while booting giving a sort of running commentary on what is happening.
I am not sure whether you need to be pressing anything on the box to get a response from the serial.
You may need a lot of patience and a cool head with this.
Sorry I did not fully answer your questions.
USB yes PC to client connector on box as you would normally do using PCTools.
Initially we are looking for messages in Putty, USB will not say connected until the USB is enabled in the box, at which point you may be prompted for the USB driver n the PC. If you get serial to work but not USB try flashing UBoot with PCTools over serial.
It might be worth running PCTools at the same time as Putty - a response from anywhere would be good, although I am not sure if PCTools will say connected when serial connection is detected.
Make sure in Putty that handshaking or flow control is disabled or set to none in the port settings. If ctrl+z does not get a reaction try pressing buttons on the box eg up, down etc
I expect my last post about the serial cable may have confused you perhaps this may help.
Example of RS232 connection.
Voltages measured without cable connected.
-12v pin2 <--------------------------> pin3 0V
0V pin3 <--------------------------> pin2 -12V
GND pin5 <--------------------------> pin5 GND
Good idea – much simpler, and good news I think. So on the male terminal on the box, Pin 2 gives no voltage and Pin 3 gives -8.6v. This comes on after the flashing LED stops – about two minutes after power on. It’s also the same measured to Pin 5 – GND. With the cable still plugged in to the PC, the female end of the connector cable gives GND to Pin 2 as -11.1v and nothing to Pin3. So it looks like my cable does do the crossover, assuming the pinout at the PC is standard. Is the disparity in voltage a worry?
Yes I think you are right if I understand what you are saying:-
PCBox PC male pin 2 0V
PCBox PC male pin 3 -8,6V
PC male pin ? cable female pin ? <---------------> cable female pin 2 -11.1V
PC male pin ? cable female pin ? <---------------> cable female pin 3 0V
So if you plug the cable into the box the negative outputs will connect to the 0V inputs - that's what we want!
Voltages are not too critical.
We need to check the port settings on the PC.
First check in device settings - do you have more than one serial port and if so are you selecting the correct one in PUTTY.
Sometimes you have a 25 pin port and a 9 pin port.
I need to try PUTTY and check if there are settings which could be causing us pain.
OK so I only seem to be able to see COM1 this may be a problem if you are trying to use another port. Set speed to 115200 and flow control to none and click open button at the bottom. Just noticed - on the left click session and make sure serial is selected and not SSH or any of the others.
If you cannot select the right port try another program - I tried TERA TERM the other day and it worked on COM4 when I used it on an old box that I was using to test it.
The fact that you get -8.6V from the box is an encouraging sign - I really think this should work!
Just tried PUTTY again you can select another port you just need to manually change it eg. change 1 to 2 to change from Com1 to Com2.
When you click open a text window opens to show the communication taking place.
By the way to get at flow control click serial at bottom left.
Yes I only have COM port and I set it to 115,200, 8bits, no parity and no flow control. Same on PuTTY and PCEditor which incorporates flash tools Trying to use FlashTools/PCEditor to flash an update image produces the message
Failed to open com port: \\.\COM1, Error No. – 51
However, no mount of Ctr+Z, standby button/right or up arrows produces any response. One thing I did check was that we had a voltage at Pin3 of the box after the standby switch LED went off. We didn’t lose it by pressing the standby button.
I have managed to duplicate your error 51 with nothing connected to my port.
It means the port is open in another application.
So forget what I said you cannot use PUTTY and Flashtools at the same time.
I have run Flashtools using Com4 in my case, set it up to flash and have the messages:-
N:COM Port Monitoring Started[20:55:15]
N:Ready(9000HD_usb_iboot_1.3.3_24 1008.img[20:55:15]
Perhaps you can do similar and push, prod, restart the box etc to try and kick it off.
Thanks in FlashTools I get it say Ready, but I can’t find a way for it to spring into action – not holding standby button and right button or up button, and powering down and then back up. Shutting that and using PuTTY I get the blank box and the green curso top left, but not beyond that.
This is very disappointing I don't have any suggestions at the moment apart from maybe shorting pin 15 and 16 on the JTAG connector to reset the box but I would think that this will be the same as power off/on. Need some time to think about this and consider what options we have left.
You could monitor the RS232 output pin from the box does it change at all? If it changes but we don't see any data we may have a serial port problem on the PC. Can we be sure the port works, have you used it for anything else?
You could disconnect the box and loop back to the PC by linking pin 2/3 on the box end of the cable then what you type on the PC keyboard should echo in the PUTTY box. I think that should work and will prove transmit/receive from PC RS232 port. Yes I tried it and it works.
You could try a lower speed setting say 9600.
I would like you to try Tera Term instead of PUTTY - will send you it by email - I think it's a simpler program with fewer settings to worry about.
I will be busy tomorrow but will check for posts when I can.
I had a thought - we have been careful to disable handshaking on the PC end but what about the box end?
The few boxes I have used with serial did not use handshaking and only used 3 wires, TX, RX and GND.
This may be clutching at straws but could be worth a try.
What you need to do is link pin7 and 8 and pin1, 4 and 6 on the box end, you can remove any existing wires.
Once again I cannot upload a file, I will email it to you.
Don't forget to try typing ctrl+z
Just an observation but I tried serial on my old Travelmate 6900HD the other day and could not get it work.
I remembered using a program before to backup settings called Clarke Tech Studio so I tried that and was able to backup settings.
So even though there was no apparent communication there seems to be some magic way to enable it at least in that case.
Perhaps there is a version of this program for IPBox you could try?
Thanks will try that later - probably tomorrow now.
I don’t think I’ve ever used the serial port on this computer for anything.
So I’ve linked Pins 2 and 3 at the female end of the cable from the PC. I open PuTTY in Serial and then type a few characters on the desktop or in MS Word, and nothing appears in the box. Same at 9600b/s and same in Teraterm.
Is that what you wanted me to try? I tried typing something in the box. Something appeared in PuTTY, but not Qwerty. In Teraterm it reproduced querty – or rather it did. Now I can’t type anything in the PuTTY box, nor in Teraterm.
I don’t think I can disable handshaking at the box end with the cable connected. Inside the box there is an 8-pin connector to the motherboard but it seems to be hard wired at both ends.
I think you are doing it right but just to recap.
Cable plugged into PC and link pins 2/3 on the other end.
For this test speed does not matter as transmit and receive should be the same speed.
If the port can't do this there is no way it will talk to the box.
Perhaps you could remove the cable and try linking pins 2/3 directly on PC port, I know it's male and probably around the back but I'm sure you can work something out.
Also check cable continuity - pin 2 and 3 one end to 3 and 2 the other, it is possible it may not be a serial cable. Of course you also need pin 5 to 5 (but not for this test).
Do you have an old serial card you can plug in and use instead or old laptop with serial port?
When I ran this test I used this laptop with a USB to serial cable and just shorted pins 2/3 and it worked on first attempt.
There is a setting in PUTTY/TERATERM for local echo, when turned on it will print in the box what it sends and what it receives, you should then see double/repeated characters eg aabbccddeeff
NB pins are numbered in opposite way on female plug:-
Female
5-4-3-2-1
-9-8-7-6
Male
1-2-3-4-5
-6-7-8-9
I've unplugged the cable and Pin 3 at one end connects to Pin2 on the other and vice versa. And there is continuity between Pins 5.
The cable should be OK then. Either the port is faulty or you have a hardware conflict in the PC it may show up in device manager, double click the port and then advanced. You can change the com port number, for some reason mine says 3 and 5 are in use and is currently set to 4. When I tried changing this the other day it did not seem to work, but knowing Microsoft it might have done after a reboot.
You could try rebooting and using BIOS/Setup - disable any ports you don't need like parallel/printer (you could also disable USB temporarily) - you may have the option to change port number, address and interrupt settings try changing these and hope for the best. Other than that it looks like you need another port. The USB serial cable I suggested (for use with Dreambox) to you was only about £3.50 but of course that will take a few days to arrive. I suspect computer shops would cost more but I have not checked.
Thanks. I have no LPT/Parallel port, no other COM ports, and Device Manager says this one is hunky dory and we know it does deliver credible voltages. So will try the Serial to USB cable.
The USB-Serial cable came very quickly. No difference though. Repeated CTRL+Z orocuces no response in either PuTTY or Teraterm.
I forgot to mention that I came across someone saying CTRL+C rather than CTRL+Z so that may be worth a try.
Please try the link back test by linking pin2+3 to be sure to be sure.
I would like some details from some devices on the motherboard, there are 4 Hynix memory chips, 2 below the CPU/Processor and 2 to the left of it. Further to the left there are 2 5-pin devices with the middle leg cut short with an ST logo on them, I want to know the details from these and also from the smaller device (3 pins?) in between these. I think these are voltage regulators or power controllers/switches or something like that I want the device types to look up data on these. Some pics of this area could also be useful and if you can manage some voltage measurements as well that would great as well - be careful not to short pins with your probes when taking readings.
There is a large resistor close to these devices please check this, I think it should be 0.5ohm. Large device close to CPU right side is a flash device please read details so I can look up data. I think we need to look for signs that the CPU is alive and doing something and that attached devices have the supplies they need to function properly.
Thanks, will got on with that later.
I've tried linking Pins 2 and 3 on the new serial female connector and typing something on the computer. There is no response either from PuTTY or Teraterm. I'm getting to wonder if there is something about my computer and these terminal programmes. Sometimes I can type in the dialogue box, sometimes not. Sometimes if I type say qwerty, I get qwerty, sometimes a string o ofther characters including backspace/delete. In Teraterm I've found where to enable echo, but haven't found anything in PuTTy. I'm running Windows Defender but nothing else I can think of.
That is really weird, how secure is your link? I would use a piece of stiff solid wire - the fact it works sometimes may suggest an intermittent connection. Do you have another PC or laptop you can try this on? I cannot find local echo in PUTTY either perhaps they left the feature out to keep the program size to a minimum. I really don't understand why it should behave like this but like I said before if it can't talk to itself it will have no chance with the box. In a way I am hoping that there is a problem with one of the voltage regulator type devices, a supply missing from the RAM's or flash chip would hopefully be an easier fault to trace. Check for hot or warm devices on the motherboard. Also if the CPU heatsink is stone cold it is probably inactive but "why?" would be the difficult question.
No, the loopback has not worked intermittently. I'm using solid phone wire, which may be a little thin, but I'm careful to jiggle it about, press it aginst the sides of the socket etc. and it did give us the expected voltage readings.
I'll get back later on the other things.
So having said that, I thought I'd better check the voltages on the new female serial cable and there are none. The old one is still connected i.e. female 9-pin to female 9-pin and that is as before. The new one shows up as SERIAL-USB CH340(COM5), and Windows says drivers up to date.