Rohde & Schwarz UPL "Keyboard error or no keyboard present" Error

ubergeeknz

Member
2018-08-31 12:32 pm
Surprising to me that a mainboard of that vintage should fail now to the point of needing replacement.. I would have a look at it and check battery (there's usually a cmos battery to maintain the settings) and tantalum / electrolytic caps. If the battery goes it can leak corrosive goo everywhere necessitating other repairs.
 
I have no experience with the UPL, but on a regular PC this error message is produced by BIOS. The usual fix is to disable keyboard check in the BIOS UI. My 2cents your BIOS setup has been changed and BIOS performs the check now. CMOS battery dead => BIOS reset to defaults? Every battery will die eventually, that could explain the problem.

Also, you can connect a USB keyboard to test if the BIOS message clears. I do not see any PS/2 port at the back, hopefully the ancient BIOS already supports USB keyboards.
 
I forgot to mention I replaced the battery annually because of this CMOS checksum problem intermittently happening. Even with a new battery, it's not remembering setup.

The keyboard error is something new that started this summer, intermittently.

I also tried reflowing the solder connections where the battery socket connects to the PCB. I measure 3.1V on the solder points on the PCB with the battery installed.

The motherboard is mounted inverted and has a card edge connector that connects one of the ISA slots to a slot on the digital board underneath it. There are some other connections as well. Handling is limited by soldered in keyboard connector which is mono strand wiring that breaks every time I flip the board over and has to be resoldered each time the motherboard is taken out.

My intuition tells me there may be a failing solder joint on the motherboard somewhere, due to the intermittent nature of the keyboard errors. But the CMOS battery failure is now a hard, always-on, failure. In the past, taking it apart and putting together again with a new battery used to fix it for a few months.
 

ubergeeknz

Member
2018-08-31 12:32 pm
Handling is limited by soldered in keyboard connector which is mono strand wiring that breaks every time I flip the board over and has to be resoldered each time the motherboard is taken out.

My intuition tells me there may be a failing solder joint on the motherboard somewhere, due to the intermittent nature of the keyboard errors. But the CMOS battery failure is now a hard, always-on, failure. In the past, taking it apart and putting together again with a new battery used to fix it for a few months.

Sounds like you're probably real warm there .. just keep at it
 

ubergeeknz

Member
2018-08-31 12:32 pm
This may help, wonder if they're doing this trick. Back in the day not many BIOS allowed you to turn off the keyboard check so this was common for headless systems (or just hide a keyboard somewhere [emoji23]).

Most systems detect a keyboard connection by monitoring the current flow
through the connector. To trick it, simple wire a 10kohm resistor between GND (pin 4) and +5V (pin 5). This is on a standard PC/AT style connector (the larger 5 pin one).
 
The UPL was designed to run without the optional keyboard. I do keep one plugged in most of the time because it makes building new setups possible with file naming and so on.

The connectors are absolutely compatible, otherwise my modern keyboard would never have worked with the UPL.

I have it booted up now, and I have decided to just leave it powered on 24/7, rather than shut down and lose all the setup again. It takes quite a while to disable a bunch of controllers and ports (the motherboard controllers conflict with the digital board's controllers, preventing the HDD from being detected).
Why they chose not to use the normal HDD controller for the disc storage, opting to put it on the controller on the digital board, is a mystery. Had it been on the normal controller, this type of fault would not keep it from booting.
The on board stuff has to be disabled. All of it. The drive specs have to be entered each time.
Oddly, only the date and time are being retained now. Everything else is gone when the power is off.
 
Lost BIOS settings while the clock is kept is weird - usually those are saved in the very same little RAM inside the RTC, and it's usually the clock that goes first.

I wouldn't rule out dodgy CMOS RAM or even a corrupted BIOS at this point (though that might rather result in something like this). It sure can't hurt to check the CMOS power circuitry very thoroughly at this point, including for leaky diodes.

Any signs of leaked capacitor electrolyte on the board?
 
Nothing LOOKS faulty, as far as corrosion, leaking capacitors, etc.
Being a multilayer PCB, the battery connections quickly vanish into the interior layers not to be traced.

My only hope would be that the BIOS chip is faulty and a replacement could be found.
My eyesight and the lack of steady hands make that fine surgery shown in your linked video not a good option for me.

This board has a lot of VIAs and the only through hole joints are the ISA slots and a few connectors. They looked pretty solidly soldered, but then, that's all I could see with a 3X magnifier and my aged eyeballs.
 

Bjirre

Member
2011-03-30 9:06 am
Maybe another way as a solution.

The UPL uses a link in the keyboard connector to check if a keyboard is present.

I could give you the pinout. It's not documented anywhere in the service manuals. A small jumper wire soldered would always tell the UPL the internal keyboard is connected.
 

Bjirre

Member
2011-03-30 9:06 am
The analyzer checks for the internal keyboard during selftest. If the link in the connector is not there it will prompt the message in the UPL software. Not sure how they skip this test for blind UPL analyzers, probably a setting inside the eeprom.

If we are talking about a bios message about an external keyboard then my comments are not applicable (am not sure where the error is shown in the previous posts). The bios will not complain about the internal keyboard as it’s not a peripheral for the motherboard according to me.
 

PRR

Member
Paid Member
2003-06-12 7:04 pm
Maine USA
> bios, to enable it to check for keyboard.

I do not know that machine. Generally the BIOS will detect and accept any keyboard it finds at pre-boot. The "option" is to stop and complain or silently continue keyboardless.

Keyboards can be plugged-in "live". (on PS/2) It is not best electrical practice but I never lost a PC that way. At the "NO KEYBOARD - PRESS ANYKEY" error, plug in the keyboard, wait a sec, press any key.

If it isn't allowing you to get past a KB error, either it is a funny BIOS or it has hardware fault.
 

Bjirre

Member
2011-03-30 9:06 am
Maybe there is a setting in the bios for periphials. At least not in mine (R&S custom Motherboard).

There is a setting to halt on errors. It that would be switched off maybe...

My best bet would be to look for a new motherboard. Rohde and Schwarz made customs but also used off the shelf boards. Then simply installing DOS and the UPL software and back to normal.

I have both the off the shelf motherboard and the custom one.

Kind Regards,

Bart