I need some Aoyue 968 help from the pros

[guilty]

I have been using the 968 for a little while now. When I first got it, the heating element was way off. I centered it the best I could, tried to check for even heat by toasting bread as well as paper but it didn't work really. The bread started warping and the paper started raising weird before it browned.

90% of my reflows were with a heatgun and thermocouples so the aoyue was a big change for me. I tried a gpu lift with a griddle and a netted nozzle from sra. I placed two thermocouples on opposite corners of the gpu like nornal. Started out with airflow at 7. I preheated the bottom of the board til it 160-170. Brang it up to 195 and lowered my nozzle to about 2mm or so. The thermocouples started out only about 5c difference from eachother. One of the thermocouples lifted a bit when I hit about 200. Anyway, I went by the one that didn't lift and got it up to 235 the first time and held for about 10 seconds, raised the nozzle carefully and tried with my little vacuum pen. It was a no go. I heated it up for longer with the airflow maxed out and brang it up to 240 and it still didn't work.

I had my heat gun right there ready for this to happen. I fired up the heat gun and brang it up to 235 for about 3 secs and got a perfect lift! I cleaned it up and it looks perfect. I gave up on the direct heat stencil. Going for the reball station soon. Too much hassle.

Sorry for the novel guys but heres my main question. Why do you guys think this happened? My thermocouple read the exact same temp. I think the heat is really uneven making a good reflow impossible too. My thermocouples are usually not more than 5-8c difference for me during a reflow with a heat gun or aoyue(unless one lifts).

I would really like to get this resolved. How can a heat gun produce better results than an actual rework station? Some help would be greatly appreciated. I am seriously thinking of going back to my heat gun.

[wilbertyl]

Best solution would be to repeat the procedure and hope the thermocouple stays put. The thermocouple reading is critical in this procedure. Where did you place the thermocouple to check for the bottom board temperature?

[NickdogV]

Clean the 2 areas where you place the tape over the thermocouples with alcohol/MEK to remove any grease or dust that is causing the tape to not stick and rise up at those high temps. Also you need to try a thermocouple in each corner of the chip to make sure it is heating as evenly as possible over the whole chip. Also what type of preheater are you using? And once you reach that bottom heat and lower your nozzle, how fast are you going up on the Aoyue?

[guilty]

The reason the tape lifted is because I used just a little bit too much alu tape. I have done it many times without fail. I place my thermocouples at the corners of the gpu.

My whole reason for this thread was to ask you guys that if a heatgun heats more evenly, why even use the aoyue? My thermocouples were at the EXACT same reading when I tried to lift the gpu VS just a heat gun. So was the preheater. Everything was exactly the same. I bought the aoyue because I thought it would heat MORE evenly. I heard there are hotspots but WOW. I've been doing reflows with it and I thought it was all good until I tried to actually lift the gpu.

My return rate on my heatgun with tc's reflows has been 0%. I haven't got any returned yet from the aoyue but it hasn't been too long.

I am about to just sell my whole aoyue 968 setup.

[NickdogV]

If it was working so well with a heatgun then why did you even order an Aoyue? That makes no sense to me. These Aoyues are made in China, they are real cheap and each one differs from the next in one way or another. I ended up having to order a new Aoyue after my first one broke after 300 repairs. Just keep messing with it until you get it right, that's what I had to do when I first got my Aoyue about 8 months ago. I went through 5 of my own consoles and 6-7 customers xboxs before finnally finding a profile that worked great.

[equisch3x]

Hmm
makes me wonder why on earth i purchased the 968 and t8280 preheater
when a heat gun works just as good?
someone please prove me wrong.
500$+ vs 20$ Heatgun...

[guilty]

@Nickdog I ordered it because I thought I could do a better job with it and because I want to start reballing. I thought it would be easier to reattach the gpu with the aoyue than with a heat gun. I 've never heard of anyone trying to reattach a reballed gpu with a heat gun. I am going to try it though.