Fluke 199 repair (non booting/corrupt rom)

[Spekham2013]

Hi,

Recently I purchased a Fluke 199 (not B/C model) in a non working state. Listed was that the meter was non-functioning and had suffered a battery leakage. When opening everything was nice and clean with the exception of the metal which was visibly corroded. When connecting power to the system and pressing the power button only a faint beep can be heard (every two presses that is). I checked the flyback converter, which was not getting the on signal. Next I tried to connect to the uart using a simple uart to usb. Here I could get into the mask rom, and test the ram, which worked. Thus also mostly concluding the D-asic is not broken.

But now comes the point where I kind of hit into a brick wall. I found the updating utility to v4.08, but I don't know the serial number of the device. So I then just tried a random number and I get the error communication error, caused by corrupted rom or uart communication problem. So I went out and bought a nearly identical pinout rom chip, and soldered it on, and guess what same error. So now I am starting to suspect the problem lies somewhere else, but I am unsure where to look.

My two ideas are:
- Read out the flash chip directly
- Desolder the D-asic and ensure no traces have corroded underneath (I have not yet seen evidence to suspect this)

Any help would appreciated, thank in advance!

[asis]

Hi,


Follow the link 
https://www.eevblog.com/forum/testgear/fluke-192-196-199-fw-upgrade/

Zip file 28F160 TE28F160B3TA10.zip (510.89 kB) is posted there.

You can see the serial number in the address range:

001F8080 - 001F80B0                1F8082 = 0801321 (7 - digit) (080132.1) "DM0801321"
&
001FA080 - 001FA0B0 (double). (1FA082-double) = 0801321

BUT!

1. Before desoldering the chip, look carefully to see if it has been removed before.

2. Chip TE28F160B3TA10 (Intel) has internal copy protection and may be blocked when trying to read / write.

3. Back cover with serial number - may be from another scopemetr.

Judging by your description, the scopemetr starts the mask verification procedure (UHM - Universal Host Mask v1.0) but does not see the required serial number.

There may be other reasons as well.

[Spekham2013]

1. The chip luckily hasn't been desoldered before as far as I can see.
2. Noted
3. There is no sticker on the back anymore

The system actually start UHM v2.1 although not sure if that information is relevant. I will see if I can get my hands on a flash programmer/reader.

[asis]

Before you connect the chip to the programmer, read carefully the pdf on TE28F160B3TA10 section 3.3
Be sure to write down the checksum the first time you read it.
Better yet, find another 28F160 chip and experiment with the dump you downloaded (zip).