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Parts for Roper RED4640YQ0 / - AppliancePartsPros.com

See the attachment for the wiring diagram.

When you say "checked the fuse on the exhaust- seems OK", did you check it with a meter?

The first ting to check is the power. The heating element requires the full 240 volts.
If you place the timer mid-cycle, timed dry does the timer advance?
If not then you probably have a power problem as the timer also uses 240 in this unit.

If the power is OK then do you have a meter?

If you do not own a meter, I would suggest you purchase a one. You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.
4. When you start always short the meter leads together. This will tell you that the meter is working and if there is any 0 offset.

There is a good STICKY at the start of this forum about it's use.

[COLOR="Blue"] how can you measure ohms and stuff without power to the machine?[/COLOR]
The meter has a battery in it. In resistance settings it creates a current through a part. It then measures this current and changes it to a resistance reading. An open circuit is infinite ohms. A closed/shorted circuit is 0 ohms.
A heating coil has some resistance so it usually measures about 10 ohms.

[COLOR="Blue"] And when they say disconnect one side of the device to measure are they talking about the power cord to the block in the dryer?[/COLOR]
When using a resistance scale the unit is always unplugged. If left plugged in then the line voltage is too high and it can blow the meter. The only power you want in the circuit is the power from the meter's battery.
But this is not what unplugging one side of a device when measuring it.
Lets say you are measuring a heater and there is another part wired in parallel with it so you measure across the meter and get 5 ohms this could be misleading. But if you disconnect one side of the heater then it is not part of a parallel circuit so you are measuring just the heater and then you should see the correct 10 ohms.

Note that there are lots of places to find info using a multimeter on the net.

[COLOR="Blue"]found out the timer is not advancing. what could i check next?[/COLOR]
I am assuming that it does not advance in timed dry as well as auto modes.
Could be a power problem.
In timed dry the timer motor circuit is: L2 , timer contacts F to T , Timer Motor , L1.
Set your meter to an AC volts scale.
Scale must be higher than 200 volts.
For instance on my meter I would use the 250 AC scale.
Remove the small cover on the back of the unit where the line cord attaches.
Measure From L1 (Black) to L2 (red) on the terminal strip you should have 240 volts.
Be very, very careful to not short out the meter leads to anything else!
240 volts is lethal!!!!
If unsure about doing this get an electrician or appliance repair person in.

If you have no voltage or 120 volts then you have to check the voltage at the wall receptacle or call in an electrician.

If you have the correct voltage, unplug the unit.
Set the timer mid scale timed try.
Measure across T to F on the timer using resistance, should be 0 ohms.
If not replace the timer.

[COLOR="Blue"]could a circuit board be the prob?[/COLOR]
No.
The unit does not have a circuit board.
see the wiring diagram I included in my earlier post.

If your model number is the same then the troubleshooting should be correct.

I do not know what part you are having a problem with.
Perhaps get a friend to take a look at it, often two heads are better than one.