Hello,
I got a few time ago a defective TDS7054 and I'm trying to repair it.
Thanks to this forum and especially this thread, I was able to perform several tests and corrective actions. Unfortunately without success.
The problem: Windows 98SE boots normally but the instrument hangs on the TekScope Splash screen.
What I have done :
- Update to firmware V2.5.5 -> no change
- Quick internal visual examination -> no trace of damage
- PPC 7 segments LED indicates normal booting sequence up to the blinking (-)
- Connexion of console port to an old laptop (fitted with COM port) -> boot listings below
- Checking of PPC NVRAM battery (PowerCap) -> dead, 0.29V. Connexion of a fresh CR2032 battery to the PowerCap with external wiring
- Attempt tu restore boot parameters from console (no need, parameters seemed correct, see below)
- PPC booting with the file executing : tcsLoadTableToNVRAM "setup.tcs". This file is named tcsTopScript.vsh in my VxBoot folder -> TekScope still hangs
- Editing of topScript.hw in order to execute "NvramClearDb = 1", then rebooting with topScript.hw restored in initial state -> no change
- Checking of the NLX board CMOS battery -> OK, 3V. Anyway, initialization of the BIOS parameters with the MSDOS command CMOS -r nonet -> no change
- Cleaning of edge connectors NLX board to riser board, and riser board to PPC board -> no change
- Checking of power supply voltages (service manual page 6.56) : all correct well within tolerances except fan voltage (should be 9.8V, measured 13.2V). I suppose fan voltage is not critical and not the source of TekScope anomaly.
- External VGA monitor connected to NLX SVGA port : displays a text saying Windows initialized the display adapter (see below).
- External VGA monitor connected to PPC VGA port : same image as flat panel.
Remarks :
- At the end of the PPC booting sequence, I can hear relays clicking, I suppose on the acquisition board.
- After power off, the NVRAM drains abnormal current from the battery : I measured varying current between 0.5 to 2mA ! However, the NVRAM test during POST does not fail.
After all this I am a little desperate
. Does someone have an idea ?
Thank you for reading,
Pascal