Manuals for Hewlett Packard This is the manuals page for Hewlett Packard. In this page you find schematic, users and instructions manuals, service manuals, technical supplement, leaf leads and other good stuff. View and Download HP 8970B service manual online. Noise Figure Meter. 8970B Multimeter pdf manual download.

Bought an HP 8920B service monitor for 'parts' on our favorite auction site. It looked to be missing a few parts but was in very nice condition. For those that don't know a service monitor is a single box that contains a RF signal generator, multiple audio generators, RF analyzer, audio analyzer, spectrum analyzer, dummy load etc.

It can generate and analyzer signals at the same time. They are generally for radio alignment.

In the case of this specific 8920B(they can have various options) it covers 0.4-1000 MHz and can handle 60 watts continuous, 120+ for 10 seconds in to its RF port. Hp Ilo 4 Keygen For Mac. It has the spectrum analyzer and high stability reference options.

It also has the signalling board which can generate and decode all sorts of analog audio data. I've always wanted an 8920B and already have an 8921A which is quite similar so I figured I'd have a decent chance of repairing it. Front: Back: It failed to boot in the pictures and was stuck at the bootloader. When I received it I noticed that it was in very nice condition. I opened it up I found something which did not inspire too much confidence, this is a side picture of the chassis: Wondering why it didn't boot I pulled the memory card and saw this: That is a lot of empty firmware sockets! In my 8921A there are OTP roms installed on those sockets.

The 8920B is supposed to be flash upgradeable though via a PCMCIA card plugged in to the front of the unit. I posted on the HP support group asking for firmware but nobody had it, and nobody could tell me what type of flash chips fit in the sockets. I traced the address lines and decided that 29F010 were the largest that could be addressed. I ordered a bunch of flash chips and also found a firmware update PCMCIA card on the same auction site I purchased the unit from. I waited for everything to arrive.

The big day finally arrived I had flash chips and a memory upgrade card. I installed 8 flash chips and plugged in the firmware update card. I was greeted with this screen: I went through the process and it completed successfully. So far this was looking very promising. I followed the instructions and rebooted, and sadly was back to the exact same bootloader screen I had started with.

I repeated the process but it made no difference. I then removed one of the flash chips and dumped it, it was totally blank. Toothpaste Two Font. At this point I decided I had to think about it a little more.

More to come. OK, lots of updates to give on this 8920B. I had another look through the service documentation I have and came to realize those sockets are supposed to be empty on an 8920B. On the 8920A and 8921A the sockets hold 27C040 OTP chips for the firmware. On the 8920B it has a different processor board with flash memory directly on the board.

So that explains why the firmware upgrade worked, but not why it didn't want to boot. I have since done a lot of work on the unit and found many bad cables/components. Here is the summary: -A5 Serial I/O controller - resoldered to fix(this allowed the unit to boot, but it had many errors) -Bad DB15-IDC14 cable going from motherboard to A23 input module - Used new ribbon cable and carefully recrimped the existing connectors to it -bad cable going to front panel - again reused the existing crimp connectors and made a new cable -CRT kept shrinking - removed CRT module and found a fuse that was loose in its holder. Gave the holder a little crimp and it is good again -Frequency counter failed self test. Found a bad 3906 transistor in the counter interpolator portion of the A19 measurement board -GPIB didn't work. Found two pins shorted on the GPIB driver IC.