EEVblog 1663 - BM786 Multimeter REPAIR + InEr Error Investigation

Repairing a customers Brymen BM786 multimeter, and investigating the cause of the InEr error message on the input jack alert feature.
Plus a giveaway to a local youngster.

Keysight OLED meter repair: https://www.youtube.com/watch?v=CKdeqqo2diI

00:00 - A returned BM786 Multimeter with InEr error message
03:23 - Split jacks and input alert circuit
05:19 - In-Circuit probing TIP and Low Ohms mode.
07:19 - A clue?
08:05 - A need a new desoldering gun. Removing the input jacks
10:30 - Bodge testing of the input detection threshold
12:38 - Not one but TWO failed Megger Insulation meters!
13:50 - Megger testing the connectors at 500V
15:19 - Testing a 2nd failed InEr error meter
17:00 - Cleaning the input jacks
19:11 - Heating up the input jacks
20:18 - Getting desperate, removing the input jacks
21:49 - Getting really desparate, removing the input resistors
22:38 - Reassembling the original repaired unit
24:26 - Repaired BM786 GIVEAWAY

Forum: https://www.eevblog.com/forum/blog/eevblog-1663-bm786-multimeter-repair-iner-error-investigation/

Web Site: http://www.eevblog.com
Hardware Store: https://eevblog.store/
Merch Store: https://www.teepublic.com/stores/eevblog?ref_id=37825

If you find my videos useful you may consider supporting the EEVblog on Patreon: http://www.patreon.com/eevblog
Or with crypto:
BTC: 33BsprBQNBtHuVzVwDmqWkpDjYnCouwASM
ETH: 0x68114e40ff4dcdd384750500501e20acf3875f8c
BCH: 35n9KBPw9T7M3NGzpS3t4nUYEf9HbRmkm4
USDC: 0x68114e40ff4dcdd384750500501e20acf3875f8c
LTC: MJfK57ujxy55su4XicVGQc9wcEJf6mAoXF

Other channels:
EEVblog2: http://www.youtube.com/EEVblog2
EEVdiscover: https://www.youtube.com/eevdiscover

#ElectronicsCreators #Repair #Brymen
...
https://www.youtube.com/watch?v=ETopbGankfo