I think I blew up my DPO3052 scope... - Page 1
Forum section: electronics / repair

author: deonv3
author_rank: Newbie
timestamp: January 26, 2024, 03:52:51 pm
content: Hello scope afficionados...I recently stripped my Tek DPO3052 scope to replace the LCD backlight. Put it back together, but now the screen just turns black upon powerup.It does power up and the fan runs and some green led's on the main board light up, but the front panel keys do nothing.I have since taken it apart numerous times to check all the plugs and wiring, tested the DC power supply and even tried an external monitor. ...Nothing... I'm at a dead end here. I can only conclude that I somehow damaged the main board during teardown, but there are no visible damage or clues...As you know, Tek doesn't provide circuit diagrams or even block diagrams.Any ideas and help will be much appreciated.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 26, 2024, 04:40:47 pm
content: have you checked all the connections, header / cables etcis the backlight really compatible ?

author: thedoc298
author_rank: Contributor
timestamp: January 28, 2024, 05:23:41 am
content: If you put the old one back in, does it do anything different than the new one..?

author: deonv3
author_rank: Newbie
timestamp: January 29, 2024, 06:37:56 am
content: Yes, the symptoms are the same with or without the screen plugged in. (using external monitor on the VGA port)I triple checked all the connections, ...checked for bent pins ...etc.

author: Psi
author_rank: Super Contributor
timestamp: January 29, 2024, 06:53:07 am
content: Are you sure all the connectors went back in the right place and the right polarity.And are you sure there's no small cable/ribbon cable you forgot to put back in (Maybe it fall on the floor or got pushed under something and you didnt realize)Or a ribbon cable you put back in upside-down, so is now pressing plastic instead of copper onto the connector pins.Or maybe a crimped ground ring that was not put back in the right location to ground something.For most engineers failure to reassemble correctly is more common than damage you did but didn't realize.If damage was done without realizing it, slipping with a screwdriver and taking out a SMT passive is pretty common. But usually you notice at the time.

author: deonv3
author_rank: Newbie
timestamp: January 29, 2024, 11:38:43 am
content: Thanks for the response.Ya, ...I must have checked all those things about 20 times over. I was very careful with the connectors and ribbon cables.The devil on my shoulder now tells me I damaged something on the main board with static because I did not wear my antistatic band at the time.

author: Vovk_Z
author_rank: Super Contributor
timestamp: January 30, 2024, 08:34:03 am
content: Quote from: deonv3 on January 29, 2024, 11:38:43 amThis is possible only if you wear a synthetic clothes. Otherwise the possibility is quite low.Possibly just some power unit is dead (was dead and still is dead).

author: deonv3
author_rank: Newbie
timestamp: January 30, 2024, 02:16:07 pm
content: I have just measured all the DC voltage test points on the main board. They are all very close to the values except one... the -5.5V measures at -6.6V ?? Will investigate this further...