Mecer lobo 1200 /VR-1200BKS Not switching on

[Grunder]

Hello guys,

I'm a TV tech and a friend has asked me to look at his Mecer inverter. I haven't connected a battery but plugged it in to the mains and it does run a lamp. The lcd screen is not illuminating. My friend says he mistakenly connected the battery reverse polarity but the Mecer site says it has reverse polarity protection and that I should check the fuses. The fuses check out ok and there is no sign of damage to most of the component's I could check with my meter. I had removed the transformer and heatsinks to check print underneath. Where do I start? Thanks, Mike

[Grunder]

Hi Guys, another customer who does pv work says he's had the identical unit with the same problem which he took to the local Mecer agents and they returned the unit unrepaired, not worth repairing.

This unit looks brand new and with Mecer saying that it has reverse polarity protection and the fact that it should be able to handle power interruptions one would think it would have not failed so prematurely? Like a bulldozer with a glass bumper. Doesn't say much for the brand. Thanks, Mike

[stj]

check the 5v or 3.3v at the lcd or microcontroller,
if it's missing you can trace it back

[Grunder]

check the 5v or 3.3v at the lcd or microcontroller,
if it's missing you can trace it back

Thanks, will do

[Grunder]

Thanks Stj, alot of switching going on and without a better oscilloscope I've decided to RNR the unit. That with the agents also saying it's kaput. Time to upgrade and do a bit of swatting