BK 9130 insanely long power up test time [FIXED] - Page 1
Forum section: electronics / repair

author: dfnr2
author_rank: Regular Contributor
timestamp: August 13, 2015, 12:03:40 pm
content: Has anyone experienced extremely long power up tests with the BK9130? I just got one that takes >30 minutes, clearly defective. It seems like it gets to some point, then starts over. And over, and over. . .BK is saying it needs to be sent in for repair, but that costs $360.It's not getting a fail, and resets at various points (getting farther as time goes on.)It almost seems as if there's some kind of glitch which either causes a uC reset, or a software hang and WDT reset, warming up as time goes on, like a semiconductor or cap warming up.Has anyone seem something similar? Does anyone have schematics for the 9130?Thanks,Dave

author: dr.diesel
author_rank: Super Contributor
timestamp: August 13, 2015, 12:06:17 pm
content: I bought a busted 9130 off eBay a few years ago. It failed startup right away, had a half dozen dead caps inside, all off brand crappy caps, easy to fix. Been good to go since.

author: dfnr2
author_rank: Regular Contributor
timestamp: August 21, 2015, 05:42:49 pm
content: Here's a quick followup.I thought the problem looked like an issue with the machine resetting, and thus re-starting the power up routine over and over. The bar graph would progress farther and farther until it finally made it through, after about 30-60 minutes. It looked like something was becoming stable as it warmed up.I could not locate schematics, and when I opened up the unit, I was disappointed to see the part numbers have been abraded off the chips. However, I did notice several bulging electrolytics.I applied some heat with a heat gun in the region of the electrolytics, and found I could quickly get through the test and into the operation mode before a reboot, but still, it was rebooting. Freeze spray took it back to rebooting during test.The most bulged cap was a 1000uF electrolytic, so I replaced all four of the 1000uF with new caps (and a 470uF soldered in parallel with one of them on the back side), and apparently, that was sufficient to get it to boot normally. The self test now takes only a second or so.I'll replace all the bulgy caps on the main board. Everything looks OK on the analog board, so I'll leave those alone for now. Then I'm sending it off for calibration.I'm not a subscriber of the recap first and debug later approach, but in this case, it was indeed bad caps.Dave

author: Kean
author_rank: Unknown
timestamp: February 19, 2016, 06:56:26 pm
content: I just hit this same issue on my seven year old BK 9130 - on power up it just kept restarting.On opening it up there was a group of 10 caps (9 on top, one underneath - a mix of 470uF and 1000uF 25V), and seven of them had obvious swelling. I desoldered them and all seven bulging ones measured high ESR and low capacitance. The other three measured OK, but I replaced them anyway.Although they were 105 degree, it looks like they weren't the best quality and mounted quite close to heatsinks.I guess I shouldn't complain - an easy fix after seven years of good service.

author: crispy_tofu
author_rank: Super Contributor
timestamp: February 19, 2016, 10:19:59 pm
content: Great that you got it fixed.

author: alank2
author_rank: Super Contributor
timestamp: May 05, 2016, 01:39:46 am
content: Just out of curiosity - how long does it normally take for the power on sequence? 10 seconds? 30? 1min?

author: dr.diesel
author_rank: Super Contributor
timestamp: May 05, 2016, 10:00:09 am
content: Probably ~5 sec.

author: alank2
author_rank: Super Contributor
timestamp: May 05, 2016, 12:10:34 pm
content: Excellent; thank you. I ordered one from eBay, hopefully it will be good.edit: I spoke too soon. Seller canceled the order on me saying he doesn't have stock on the item...