i went back and remeasured and noticed i do get readings on all configurations. but it seems to change readings when i switch probes from positive on mosfet, and neg on jumper, to negative on mosfet and positive on jumper.
so yes all readings are in mega ohms range. also did notice under that specific jumper, it appears there is only solder on one of the contacts for the mesha board out of three total.
so yes all readings are in mega ohms range. also did notice under that specific jumper, it appears there is only solder on one of the contacts for the mesha board out of three total.
There must be one connection between each of the SMD transistor's terminals (transistor circled in the photo) and one of the terminals of the jumper. If there isn't, that's a problem.
The jumper MUST be soldered to the MEHSA insulator.
The jumper MUST be soldered to the MEHSA insulator.
the jumpers aren't soldered to the insulators right now, they are held on with the screws with the plate that pushes down the pins to touch the contacts on the mehsa boards.
the thing i noticed is out of the 3 contacts on the mesha board i looked @, only one seeed to have solder on it. like the solder is gone.
maybe it melted off when i was torching the boards.
so should i "add" solder back to the contacts, or physically solder them to the mehsa boards?
the thing i noticed is out of the 3 contacts on the mesha board i looked @, only one seeed to have solder on it. like the solder is gone.
maybe it melted off when i was torching the boards.
so should i "add" solder back to the contacts, or physically solder them to the mehsa boards?
Yes. You'll have to remove the board from the sink to do it. When soldering them down, make sure that the same angle it be when clamped down. When you get the board back in the sink, push the insulator against the heatsink and heat each leg of the jumper to relieve the tension on the legs.
so could this be causing my issues i am having now?
the contacts are also very dirty, caked with heat sink compound.
the contacts are also very dirty, caked with heat sink compound.
okay first photo is GOOD contacts.
100_0884.jpg picture by grandam88 - Photobucket
second photo is bad contacts. i have cleaned them. but you can tell there is basically no solder on the outer contacts. also before cleaning them, there was heastink compound filling the voids where the solder used to be, and if i am not mistaken, heatsink compound isnt conductive.
100_0883.jpg picture by grandam88 - Photobucket
An externally hosted image should be here but it was not working when we last tested it.
100_0884.jpg picture by grandam88 - Photobucket
second photo is bad contacts. i have cleaned them. but you can tell there is basically no solder on the outer contacts. also before cleaning them, there was heastink compound filling the voids where the solder used to be, and if i am not mistaken, heatsink compound isnt conductive.
100_0883.jpg picture by grandam88 - Photobucket
While it's away from the insulator, confirm that you have a direct connection (~0 ohms) between one of the terminals on the SMD transistor and one of the solder pads (on the insulator) for the jumper.
Also confirm that you have no connection (all OL) between all jumper pads on the insulator and the terminals on Q2036. Check all combinations possible.
Also confirm that you have no connection (all OL) between all jumper pads on the insulator and the terminals on Q2036. Check all combinations possible.
on the terminals of smd transistor and solder pads i have OL. all combination's.
on solder pads to q2036 i have all OL all combination's.
but on solder pads to back of mesha boards i have readings in m ohm range.
i have tried to solder the legs to solder pads for about 20 mins, they wont stick no matter what. then something came off looked kind of like a "leg" of something or maybe the "protector" between mesha board and solder of solder pads. i dunno.
on solder pads to q2036 i have all OL all combination's.
but on solder pads to back of mesha boards i have readings in m ohm range.
i have tried to solder the legs to solder pads for about 20 mins, they wont stick no matter what. then something came off looked kind of like a "leg" of something or maybe the "protector" between mesha board and solder of solder pads. i dunno.
i threw away the little "leg looking thing" i can send more photos of the solder pads.
also every time i clean the solder pads, i get a metal looking surface, then when they dry(alcohol), they turn white again.
also every time i clean the solder pads, i get a metal looking surface, then when they dry(alcohol), they turn white again.
is there some kind of protective barrier between the solder pads and the mesha board? cause i have noticed when i measure from solder pad to back of mesha i get an ohm reading on damaged board, where as on another board, i don't get any ohm readings.
also when measuring from solder pad to surface mounted transistor, i don't get any ohm reading, where as on undamaged board i get a reading to the surface mounted transistor.
also when measuring from solder pad to surface mounted transistor, i don't get any ohm reading, where as on undamaged board i get a reading to the surface mounted transistor.
alright went hunting for the metal shaving looking thing and found it. this came off while soldering the pads.
For the solder pad that was turning white, was that on the MEHSA insulator or on the main board?
Post a photo if it was on the insulator.
Post a photo if it was on the insulator.
this turning "white" was on the insulator. i cleaned it repeatedly, not it coming out to where i can see the metal. but i feel this is the front of the mesha board. not getting ohm readings from pads to surface mounted transistor. i have a feeling i damaged it somehow. here the pic of its current state.
They appear to be OK. Measure the resistance from the top of each solder pad to the bottom of each solder pad. All should read ~0 ohms.
If they do, confirm the connections to the SMD transistor. Compare the readings to the jumper and SMD transistor for the other channel.
If they do, confirm the connections to the SMD transistor. Compare the readings to the jumper and SMD transistor for the other channel.
i found another set of jumpers that are not soldered to the mesha.
as far as the ohm readings, i measured the other one without soldered legs to mesha got all OL on all configurations to the transistor. i got OL on all measurements to transistor from solder pads to transistor on the previous one with non soldered jumpers. i have noticed the jumpers on other channel are soldered. on readings from top to bottom of solder pad all read OL.
heres a pic of the newly discovered non soldered jumper legs. you can see the white layer of stuff on solder points on this one.
as far as the ohm readings, i measured the other one without soldered legs to mesha got all OL on all configurations to the transistor. i got OL on all measurements to transistor from solder pads to transistor on the previous one with non soldered jumpers. i have noticed the jumpers on other channel are soldered. on readings from top to bottom of solder pad all read OL.
heres a pic of the newly discovered non soldered jumper legs. you can see the white layer of stuff on solder points on this one.
when i do as described in picture i get .4 ohm. but i touched my probes together and get .4. so yes i get OL when i do that test.
Houston, we have a problem.
If you meter probes are in free air, not touching anything, what does the meter read?
If you meter probes are in free air, not touching anything, what does the meter read?
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