[Joe]

Thanks, so The 'lever/plunger' and smaller contacts on the T70 camera work to indicate the flash is there, sound like they working fine.
The main contact triggering the flash sounds to be at fault. more likely the camera hotshoe contact, unless the flash contact makes good on the other camera but not on the T70 (more unlikely but not unknown)
Short of trying the T70 with another flashgun to totally rule out flash unit itself, it sounds like a broken/ weak contact under the hotshoe plate (a jewellers screwdriver and soldering iron to fix), OR a poor/broken connection further down toward the shutter assembly.....major surgery to get at. I asked if the T70 has a PC socket as if a flash can be fired from that, it would suggest the camera hotshoe electrical contact, rather than further toward the shutter assembly. Unfortunately PC sockets don't provide any dedication ie flash ready symbols etc.

Either way I would be tempted to hook up another flashgun (spare/borrowed/ or basic one bought for pennies on ebay) to the T70 to totally rule out flashgun issues. My reasoning being that normally cameras do usually tend to outlast flashguns on the whole.....

only then if still not working would I crack open the screwdrivers case and heat up the soldering iron