Archos 80c tablet, no turn on , black screen Anyone solved this one  - Page 1
Forum section: electronics / repair

author: cleanworkbench
author_rank: Regular Contributor
timestamp: January 18, 2018, 07:52:25 am
content: Probably not the right forum, but i,ve had it with the archos help sites . I have an Archos 80c Xenon tablet and it has just expired , apparently the battery is fine , the reset sequence is useless , so what next can i do has anyone solved this one ?, is it a processor fault / design fault or has it got a designed life span to get you to go back and buy another newer product .Is it time to open the case and have a look see, maybe an onboard fuse??Any help appreciated here .

author: SMdude
author_rank: Frequent Contributor
timestamp: January 18, 2018, 08:36:54 am
content: Err, you are going to have to give us a little more info than that!What does/doesn't it do?As for time to open the case, its always time to open the case!!

author: Terry01
author_rank: Frequent Contributor
timestamp: January 18, 2018, 09:08:02 am
content: Maybe put a description in the title, Save people reading a post about a cheap tablet they probably won't know about.

author: cleanworkbench
author_rank: Regular Contributor
timestamp: January 18, 2018, 11:02:12 am
content: I knew as soon as i punched the button i should have put a title , how do i change title then please ?Psu plugged in , hold down start and volume up button and thats it , NOTHING, no sign of life complete black screen.

author: kalel
author_rank: Frequent Contributor
timestamp: January 18, 2018, 11:06:00 am
content: I have no idea about the tablet, but could you describe the issue as well as possible? This would help someone who might know more.Did the tablet show any signs of issues before it stopped working?Does it have some LEDs (e.g. power/charging LED)?You said apparently the battery is fine, how do you know this, does the tablet show a battery status?

author: Bashstreet
author_rank: Frequent Contributor
timestamp: January 18, 2018, 11:18:43 am
content: It is very hard to tell from such symptomsWhat really is needed is someone who can open it up check the voltages to give a bit of idea what can be the issue.It could be something simple or something that is not economical to repair.Maybe someone who has experience of this tablet knows some common error and can give some further advise lets hope so.

author: Shock
author_rank: Super Contributor
timestamp: January 18, 2018, 01:55:14 pm
content: 1. Are you intending to repair this and have the tools and a bench supply, multimeter (oscilloscope if required)?2. If not and you are willing to have it repaired how much money or time are you going to spend?I can tell you now the most common fix for a non booting device is to confirm the external power/charger is operating correctly then remove the devices battery and try on external power, if the device is several years old and the battery has been fading or left uncharged the battery is probably the culprit.Then it would be power the device via the internal battery terminals with a bench or alternate power supply. Or use a multimeter to verify the device is receiving power and that the charging circuit is operating or some other visual indication.After that it's anyones guess.

author: Armadillo
author_rank: Super Contributor
timestamp: January 18, 2018, 02:20:54 pm
content: Yes, there is a minimum battery threshold voltage before the unit will begin to start up, even if you plugged in external power supply.The first would be to use a external charger with digital display so you can tell if the unit charge up properly or not charging at all or already shorted out.

author: cleanworkbench
author_rank: Regular Contributor
timestamp: January 18, 2018, 09:02:34 pm
content: Well it did display a possible harmful app it just pinged up and it said un install and thats what was done . Continued using and was fine then was powered off and never able to turn on.Thanks i will try those suggestions

author: Terry01
author_rank: Frequent Contributor
timestamp: January 21, 2018, 04:23:16 pm
content: YouTube could be your friend here. Maybe just needs a hard reset/bios chip reset or something simple. Other than that like most of the guys say it could be 100s of things.Have you managed a hard reset?

author: cleanworkbench
author_rank: Regular Contributor
timestamp: January 21, 2018, 07:33:25 pm
content: Thanks for the tip , i went on you tube and found several people who had got the case open , thats the first hurdle.Before i went for the system functions i gave the connections a good inspection , they are covered in black cotton sticky tape , there are several . The one to the right of the speaker at the base of the battery is about 15mm long has a ribbon cable and clip assembly , the brown ribbon cable did not look fully home and the clip was not fully click shut so i lifted the clip up and pushed it fully home and made sure the clip was fully shut down ! most likly poor assembly at the factory.Everything else looked OK.Now measured battery volts , it showed 3.08 volts , i dont know much about li-ion batterys but its marked as a 3.7 volt unit, i figured its not wise to go below 3v . The unit must operate in a narrow voltage band.Tried again a turn on and there was a very faint glimmer on the screen but that was all .Tried plugging in the d.c. charger mini d plug and found when moved around in the socket for a moment the screen charging logo came on and read , zero % charge !!!. Next , manipulated the charger mini d plug and the screen read charging , the mini d plug looks like it has been slightly bent over and possibly the internal connections have been fractured causing an intermittent fault.The unit was also kept in temps just above freezing !!!So now 6 hours later it reads 100% charged and the unit appears to function ok, the voltage on the battery terminals is now 4 volts.I think it was a combination of things that lead to the fault.OK so i,m happy now , we will see how it goes. Deffo going to buy a new charger lead though.Thanks all for the help.

author: Bashstreet
author_rank: Frequent Contributor
timestamp: January 21, 2018, 07:48:03 pm
content: Great

author: Gyro
author_rank: Super Contributor
timestamp: January 21, 2018, 07:49:44 pm
content: Quote from: cleanworkbench on January 18, 2018, 11:02:12 amBefore you wrap up the thread, you can change the title by just editing your original post and changing it there.

author: Terry01
author_rank: Frequent Contributor
timestamp: January 21, 2018, 07:51:25 pm
content: Awesome!That's great news you got it fixed!

author: cleanworkbench
author_rank: Regular Contributor
timestamp: January 21, 2018, 09:33:24 pm
content: Yep job done , i hope .Title changed too, just was,nt thinking about a correct title .Thanks people

author: Terry01
author_rank: Frequent Contributor
timestamp: January 21, 2018, 11:59:09 pm
content: The answer to your question is.....yes someone solved it...YOU!!

author: cleanworkbench
author_rank: Regular Contributor
timestamp: January 22, 2018, 08:37:15 am
content: yepThanks