Instek GDS-806c DSO Won't boot up.  - Page 1
Forum section: electronics / repair

author: Aerobyrd93
author_rank: Contributor
timestamp: September 15, 2015, 07:56:30 pm
content: So I bought this oscilloscope in the hopes of fixing it up, making it run, all that. Now I've got it and am a little intimidated. Basically the symptoms are quite simple: when you push the power on, the fan turns on, and a gray screen is given indefinitely. It looks to me that it is not booting up. Any button presses, percussive maintenance or external stimulus has thus far been met with no response. Sending it in would cost more than it is worth, so I still want to fix it. Any advice will be greatly appreciatedThanks.

author: tautech
author_rank: Super Contributor
timestamp: September 15, 2015, 08:28:33 pm
content: You don't say what equipment you have for fault analysis.You'll probably need a Service manual too, find one and post a link.Start with PSU for correct values and low ripple.

author: OldSchoolTechCorner
author_rank: Frequent Contributor
timestamp: September 15, 2015, 08:45:05 pm
content: First thing is to check voltages and for excessive ripple from power supply, then go from there. As if power supply not working correctly nothing else will. Also look inside for any signs of blown components, or anything that doesn't seem right. reseat all cables. You want to try to find a service manual, will make it a lot easier to troubleshoot and won't seem as scary to work on, as take you though troubleshooting procedures and break it down to sections. Not familiar with this model of scope, but are there any error codes, or any way to pull them up due to not posting all the way and may not be passing self tests, if errors codes come up? That will give you a clue to section that having issues.

author: Aerobyrd93
author_rank: Contributor
timestamp: September 15, 2015, 09:05:52 pm
content: Quote from: tautech on September 15, 2015, 08:28:33 pmSure.http://www.electroninvest.com/shop/items/instek/GDS-800-user_manual.pdfIt's a bit generic, as it is for the whole series of scopes, encompassing different capabilities, etc, but it's what they have.I have a couple multimeters, an old 100mhz analog scope, and a power supply made from an atx psu, which gives pretty low noise. If needed, I have some access to a better desktop psu, which would actually give the +/-15v this thing uses, but would have to wait a while to use it.Thus far, I've checked that the fuse is good, which it unfortunately is, have checked the power supply outputs which are all correct, low noise voltages, and have visually checked the capacitors for damage. So far I have not been able to find anything other than the user manual and programming manual.

author: Aerobyrd93
author_rank: Contributor
timestamp: September 22, 2015, 09:16:41 pm
content: Hi there,So I've been going over and over this thing, and can find nothing visually wrong with the board, or any of that, However, I do have a burned in pattern on the lcd screen. I'm thinking there is a chance it is the lcd itself that is bad. I have yet to find a way to make the machine do anything yet without the screen though. Should I be expecting to hear noises, beeps, relays, anything while manipulating the controls? does anyone know whether a burned in pattern on an lcd would be likely to render it completely unresponsive, rather than simply having like an outline when powered on, or even if there is a way of repairing it? I haven't been able to find a direct replacement yet, but if that's not the only problem, I'd just as soon not spend the money on it, either, so I'd prefer to have some confirmation.Thanks!